Dowel pin



HHHHH D\ DDDDDD IN 15, 1932 2 Sheets Sheet 2 Patented June 20, 1933' UNITED STATES rATENT OFFICE HENRY F. HOWARD, 013 DETROIT, MICHIGAN, ASSIG'NOR TO WHITMAN & BARNES,

I INCORPORATED, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN DOWEL PIN Application filed August 15, 1932. Serial No. 628,918.

This invention relates generally'to dowel ing operation. Following the groove formpins and consists of certain novel features ing operation the body is then heat treated of construction that will be hereinafter more and is subsequently centerless ground to fully described and particularly pointed out provide the finished article.

i the appended claims. In use, a dowel pin such as that described 50 In the accompanying drawings: ll leln may be employed wherever desired to Figure 1 is a ertical qeqtiongd iew hOldadJaCent OI abutting plOCGS in proper through a punch press head and tool retainer relatlon to each other. However, for the purbody and showing a dowel pin bodym pose of illustration 1 have shown the dowel my invention applied thereto; in the body B of a punch retainer and in the 55 Figure 1A is an enlargement of a portion ram or head C of the punch press to which of Figure 1; such body B is bolted. To apply the dowel it Figure 2 is an elevation of the blank fro is Inerely necessary to drill in the body 13 and which the pin is formed after opposite ends head C holes 6 and 7 respectively that are f th yli d i l b d f l arbo st l .00 5 to .007 inches. smaller in diameter and to 60 h b t d; drive the dowel into said holes. Usually the Fi 3 i a i f th i ft th bodyB of the retainer is hardened steel, congrooves have been formed in the structure q fly the ges 8 and 9 respectively of illustrated in Figure the grooves will be fiattened somewhat into Figure 4 is a sectional view taken on the the rellef pQ 5 lnsurlng a g fit Ofthe 65 line of Figure dowel in sa1d body, and the head C is a cast- Figure 5 is an elevation of the construc g cpnsequenfly the edges 8 and 9 W 1 tion illustrated in Figure 3 after the grindmam mtact and,the metal of sllch'castlng W111 g ooeration; be sheared by said edges and w ll flow 1nto the Figure 6 is a sectional view taken on the grooves 3 and Thus 1t W111 be Observed 70 lin 6-6 of Figure 5; that the edges 8 and 9 of the grooves consti- Figure 7 is a diagrammatic View of the tute cutters to produce a shearing action. As peripheral portion of the dowel pin brought result t dowel Pm W111 Shear Itself. to into a horizontal plane. tlght fit 1n the head C. In this connection it Referring now to the drawings wherein i be noted that the provlslon of the i p 75 I have illustrated one embodiment of my infight i left hand grooves 3 i 4 W111. vention, the dowel pin preferably comprises 1 slmultageousa and centralized actlon' a cy i y A having a tapered end e grooves an s also constitute outlets 1 and provided from a end to its pp for a r in the holes when inserted therein and provide chip spaces and passa es for lubri- 30 end with crossed spiral grooves 3 and 4: recant when lubricant is used Due to the sp yand fl ie substantlany' spiral formation of the grooves, thechips (ilamond Shaped l' pormfns Will move longitudinally of the grooves upon lnthe Process of construct lol}, y insertion of the dowel into the hole 6. The

40 cal body of low carbon steel s initially T crossed formation of the grooves will insure 85 vided and 1S apered at one end as shown. such chips being divided, consequently re- A rolling operation similar to that employed sistance is minimized. The relief portions 5 for making screw threads is then employed lessen friction and the p essure reduired for for making the grooves 3 and i l. The relief forcing the dowel into if oles. Such relief portions 5 are formed as a result of this i-ollportions also provide oi time for the edges so of the grooves when the dowel is driven into hardened metal such as into the hole 7 in the body B and serve as pockets for lubricant when such is used.

Thus from the foregoing it will be apparent that I have provided an extremely practical and efficient dowel pin and that due to the construction thereof it is unnecessary to ream or otherwise fashion the holes for the dowel before insertion thereof as in the past. Moreover there is no spalling or building up of the metal that is commonwith plain dowel pins.

While it is believed that from the foregoing description the nature and advantages of the invention will be readily apparent, I desire to have it understood that I do not limit myself to what is herein shown and described and that such changes may be resorted to.

when desired as fall within the scope of what is claimed.

What I claim as my invention is:

1. A dowel pin -comprising a substantially cylindrical body having grooves constituting outlets for air in holes in which thepin is inserted, having cutting edges at opposite sides of said grooves, and having relief portions adjacent said cutting edges.

2. A dowel pin comprising a substantially cylindrical body having intersecting right and left hand spiral grooves extending longitudinally thereof with the points of intersection in lines disposed at substantially diametrically opposite sides and extending longitudinally of said body, the edges of said grooves forming cutters to produce a shearing action. 3. A dowel pin comprising a substantially cylindrical body having intersecting right and left hand spiral grooves extending longitudinally thereof, and having substantially diamond-shaped relief portions between the points of intersection and bounded by said grooves.

4. A dowel pin comprising a substantially cylindrical body having a taperedend, hav

ing intersecting right and left hand spiral" grooves extending longitudinally thereof from said tapered end, and having substantially diamond-shaped relief portions between the points of intersection and bounded by said grooves.

5. A dowel pin comprising a substantially cylindrical body having two longitudinally extending rows of substantially diamondshaped relief portions, said rows being at substantially diametrically opposite sides of said body, and right and left hand spiral grooves extending longitudinally of said body and crossing one another between said relief portions at points substantially coinciding with the longitudinally median lines of said tows. 6. A dowel pin comprising a substantially cylindrical body having right and left handlongitudinally spiral grooves extending 55 thereof and constituting outlets for air in a.

hole in which the pin is inserted and providing continuous passages for chips and for a lubricant when a lubricant is used, the edges of said grooves forming cutters to produce HENRY F. HOWARD. 

